package com.hmdp.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.aop.framework.AopContext;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * 创建订单
 * time：2023/3/31
 */

@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;

    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1.查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        // 2.判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀尚未开始！");
        }
        // 3.判断秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀已经结束！");
        }
        // 4.判断库存是否充足
        if (voucher.getStock() < 1) {
            // 库存不足
            return Result.fail("库存不足！");
        }
        Long userID = UserHolder.getUser().getId();
        synchronized (userID.toString().intern()){
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }
    }

    /**
     * 创建订单
     * @param voucherId
     */
    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        // 5.一人一单
        Long userId = UserHolder.getUser().getId();

        // 5.1.查询订单
        int count = query().eq("user_id", userId)
                .eq("voucher_id", voucherId).count();
        // 5.2.判断是否存在
        if (count > 0) {
            // 用户已经购买过了
            log.error("用户已经购买过一次！");
            return Result.fail("一人只能买一单");
        }
        // 6.扣减库存
        //解决超卖问题
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1") // set stock = stock - 1
                .eq("voucher_id",voucherId).gt("stock", 0)
                // where id = ? and stock > 0
                .update();
        if (!success) {
            // 扣减失败
            log.error("库存不足！");
            return Result.fail("库存不足");
        }

        // 7.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        long orderID = redisIdWorker.nextId("order");
        voucherOrder.setId(orderID);
        voucherOrder.setUserId(userId);
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        return Result.ok(voucherOrder);
    }
}
